School of Life and Environmental Sciences, Faculty of Science & Technology, Deakin University, 221 Burwood Highway, Burwood, VIC 3125, Australia.
Marine Apex Predator Research Unit (MAPRU), Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth 6031, South Africa.
Biol Open. 2021 Apr 1;10(4):bio055475. doi: 10.1242/bio.055475.
Understanding energy use is central to understanding an animal's physiological and behavioural ecology. However, directly measuring energy expenditure in free-ranging animals is inherently difficult. The doubly labelled water (DLW) method is widely used to investigate energy expenditure in a range of taxa. Although reliable, DLW data collection and analysis is both financially costly and time consuming. Dynamic body acceleration (e.g. VeDBA) calculated from animal-borne accelerometers has been used to determine behavioural patterns, and is increasingly being used as a proxy for energy expenditure. Still its performance as a proxy for energy expenditure in free-ranging animals is not well established and requires validation against established methods. In the present study, the relationship between VeDBA and the at-sea metabolic rate calculated from DLW was investigated in little penguins () using three approaches. Both in a simple correlation and activity-specific approaches were shown to be good predictors of at-sea metabolic rate. The third approach using activity-specific energy expenditure values obtained from literature did not accurately calculate the energy expended by individuals. However, all three approaches were significantly strengthened by the addition of mean horizontal travel speed. These results provide validation for the use of accelerometry as a proxy for energy expenditure and show how energy expenditure may be influenced by both individual behaviour and environmental conditions.
了解能量利用对于理解动物的生理和行为生态学至关重要。然而，直接测量自由生活动物的能量消耗具有内在的困难。双标记水 (DLW) 方法广泛用于研究一系列分类群的能量消耗。尽管 DLW 数据收集和分析可靠，但既昂贵又耗时。从动物携带的加速度计中计算得出的动态身体加速度 (例如 VeDBA) 已被用于确定行为模式，并越来越多地被用作能量消耗的替代指标。然而，它作为自由生活动物能量消耗替代指标的性能尚未得到很好的确立，需要与已建立的方法进行验证。在本研究中，使用三种方法研究了小企鹅 () 中 VeDBA 与从 DLW 计算得出的海上代谢率之间的关系。简单的相关性和特定活动的方法都被证明是海上代谢率的良好预测因子。第三种方法使用从文献中获得的特定活动能量消耗值并不能准确计算个体消耗的能量。然而，通过添加平均水平行进速度，所有三种方法都得到了显著加强。这些结果为使用加速度计作为能量消耗的替代指标提供了验证，并展示了能量消耗如何受到个体行为和环境条件的影响。
